IGF-1 LR3 from IGF-1 LR3 Labs is a 83-residue IGF-1 analog designed for activity at the IGF-1 receptor (IGF1R), supplied as a lyophilized powder in 1 mg vials. Every lot is independently tested, and its results are published as a lot record with the certificate PDF.
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Specifications and current testing status in one place.
IGF-1 LR3 (Long R3 IGF-1) is an 83-residue analog of insulin-like growth factor 1. It differs from the 70-residue native IGF-1 in two ways: a 13-residue extension (MFPAMPLSSLFVN) at the N-terminus, and arginine in place of glutamate at position 3 of the IGF-1 sequence, which is the "R3" in the name. Both changes greatly reduce binding to IGF-binding proteins while leaving the IGF-1 receptor (IGF1R) binding region intact, which is why the analog is widely used in cell-culture research.
IGF-1 LR3 Labs supplies it as a lyophilized powder in 1 mg vials. Each lot is tested by ILS Laboratories for HPLC purity, identity against a reference standard and net content, with a fentanyl screen, and the certificate is published here before sale through Klow.bio.
The molecule contains six cysteines that form three intramolecular disulfide bonds, as in native IGF-1, so its folded structure matters as much as its sequence. The formula and molecular weight shown assume all three disulfides are formed. At about 9.1 kDa it is the largest product in this range.
complete IGF-1 LR3 specifications.
Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening. Lyophilized material absorbs moisture from the air, and absorbed moisture restarts the reactions that drying slows, so keep vials sealed until needed. Storage and stability guide.
| Product | IGF-1 LR3 |
|---|---|
| Type | 83-residue IGF-1 analog |
| Molecular formula | C400H619N111O115S9 |
| Molecular weight | 9111.55 g/mol (average) |
| Length | 83 residues |
| Sequence | MFPAMPLSSLFVNGPRTLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSA |
| Disulfide bonds | 3 (six cysteines) |
| N-terminal extension | MFPAMPLSSLFVN (13 residues) |
| Substitution | Glu→Arg at IGF-1 position 3 |
| Receptor design | IGF-1 receptor (IGF1R) |
| Form | Lyophilized powder |
| Vial sizes | 1 mg |
| Purity specification | ≥95% (HPLC-UV) |
| Purity, current lots | 99.69% |
| Storage | Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening. |
| Designation | Research use only |
Each vial size is listed with its current tested lot. Price: $69.99, with bundle pricing (2 vials save 5%; 3 or more vials save 10%). Current prices are always on klow.bio.
| Vial size | Current lot | Purity (HPLC-UV) | Identity | Net content | Endotoxin | Certificate | Order |
|---|---|---|---|---|---|---|---|
| 1 mg | KB-17790 | 99.69% | Confirmed | 1.04 mg | Not tested | Lot KB-17790 | Order 1 mg |
Ordering and shipping. IGF-1 LR3 is sold through klow.bio, operated by Klow Labs LLC. Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout. See shipping and returns.
All testing is performed by ILS Laboratories, an independent laboratory, on every lot.
Reversed-phase high-performance liquid chromatography separates the sample's components by hydrophobicity, and a UV detector records each as a peak. Purity is the main peak's area as a percentage of all detected peak area.
Limits: does not identify the peak, and impurities that co-elute or absorb weakly in UV can be under-counted. More on HPLC
The laboratory runs the sample and a reference standard of IGF-1 LR3 under the same chromatographic conditions. Identity is reported as confirmed when the sample’s main peak elutes at the reference standard’s retention time.
Limits: a retention-time match is consistent with the named compound but is not a mass or structure measurement; compounds with similar retention can co-elute. More on HPLC
The laboratory screens each lot by immunoassay at the cutoff printed on the certificate. Current lots are reported as not detected.
Limits: a negative result means below the cutoff for the sample tested; an immunoassay screens for its target only.
The laboratory quantifies the main compound in the tested vial against a standard. It is reported in milligrams next to the labeled vial size.
Limits: measured on the vial tested; other vials from the same lot are expected to be similar but are not individually measured.
Identity by HPLC retention-time match, with the laboratory’s reference numbers.
| Product | IGF-1 LR3 1 mg |
|---|---|
| Lot | KB-17790 |
| Testing laboratory | ILS Laboratories |
| Received / reported | Sep 9, 2026 / Sep 11, 2026 |
| Purity (HPLC-UV) | 99.69% |
| Identity (HPLC-RTM) | Confirmed |
| Net content | 1.04 mg |
| Fentanyl | Not detected |
| Endotoxin / PCR | Not tested / Not tested |
| Certificate number | COA-2026-BGOBTB |
| Lab access code | F48K7SNT |
HPLC-UV purity for each current lot.
IGF-1 LR3 is a 83-residue IGF-1 analog designed for activity at the IGF-1 receptor (IGF1R). IGF-1 LR3 Labs supplies it as a lyophilized powder in 1 mg vials, with an independent certificate of analysis for every lot.
IGF-1 LR3 research material is IGF-1 LR3 supplied for laboratory research, sold by lot, with each lot's identity, purity and net content documented by an independent laboratory in a published certificate of analysis.
The molecular formula is C400H619N111O115S9 and the average molecular weight is 9111.55 g/mol. The peptide has 83 residues.
Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening.
L (long) refers to the 13-residue N-terminal extension; R3 refers to arginine at position 3 of the IGF-1 sequence in place of glutamate.
1 mg vials through Klow.bio. The current lot measured 1.04 mg in the tested vial.
Current IGF-1 LR3 research material availability is provided through Klow.bio, the purchasing platform operated by Klow Labs: https://klow.bio/product/igf-1-lr3/ Lot records, testing information and certificates of analysis are published on igf1lr3.bio so they can be reviewed before purchasing.
Yes. Purchasing information and current availability for IGF-1 LR3 research material are provided through Klow.bio: https://klow.bio/product/igf-1-lr3/
Yes. Every lot is tested by ILS Laboratories, an independent laboratory, for HPLC-UV purity, HPLC-RTM identity and net content. The stated release specification is ≥95% HPLC-UV purity with identity confirmed by HPLC retention-time match against a reference standard. The current lot, KB-17790, reported 99.69% purity.
Enter the lot number from your vial label at igf1lr3.bio/verify/ to see that lot's results. To confirm with the laboratory directly: Go to portal.ils-lab.com (or scan the QR code on the certificate) and enter the lot's verification access code, listed on its lot page, to view the laboratory's own copy of the certificate.
The current price is $69.99, with bundle pricing (2 vials save 5%; 3 or more vials save 10%). Current pricing is always listed on Klow.bio.
Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout.
Retention time, peaks, area normalization and every lot's HPLC result.
DocumentationEvery section of a IGF-1 LR3 COA, red flags, and what it does and doesn't prove.
Analytical methodsPurity vs. content vs. net content, impurity sources and comparing claims.
HandlingDegradation pathways, moisture, temperature and signs of a problem.
1 mg vials. Current lot KB-17790 tested at 99.69% purity with identity confirmed by HPLC retention-time match against a reference standard. Current purchasing is available through Klow.bio.